1. Technical Field
Example embodiments of the present invention relate in general to configuration of control channel including control information and detection of the control information, and more specifically, to a method for configuring and detecting control channels and an apparatus for the same.
2. Related Art
In addition to data channels, there exist control channels specifically designed in mobile communication systems. For example, in a Third Generation Partnership Project (3GPP) Long-Term Evolution (LTE) system, a Physical Control Format Indicator Channel (PCFICH), a Physical hybrid-ARQ Indicator Channel (PHICH), and a Physical Downlink Control Channel (PDCCH) are defined as downlink control channels. A Physical Uplink Control Channel is defined as uplink control channel. Especially, the PHICH is a channel transmitted by a base station and received by a terminal, and includes Hybrid Automatic ReQuest (HARQ) acknowledgement (ACK) information for uplink data channel. The PUCCH is a channel transmitted by a terminal and received by a base station, and includes HARQ ACK information for downlink data channel.
In 3GPP LTE, multiple control information (such as HARQ ACK information) may be transmitted by using the same time-frequency resource. This is called as Code Division Multiplexing (CDM). Also, there exists a system such as IEEE 802.16e which allocates time-frequency radio resources orthogonally and transmit multiple HAR ACK information as multiplexed by using orthogonal time-frequency radio resources.
On the other hand, as usages of applications transmitting a large amount of information by using a smartphone even during movement increase, loads of mobile communication network are rapidly increasing and the problems of network failures and degradation of service quality are becoming more severe due to the increased network loads.
Device-to-device (D2D) communications are considered as a solution for the problems. The D2D communications may mean a communication manner which enables adjacent terminals located in the same cell or adjacent cells to communicate directly with each other without a base station.
In the D2D communications having characteristics different from those of the conventional communications, there is a problem that conventional control channels used for communications between a base station and a terminal may not be efficient.